Implications of beneficial off-target effects for upcoming eradication campaigns (measles and polio)

Transcription

1 Implications of beneficial off-target effects for upcoming eradication campaigns (measles and polio) Ane Bærent Fisker, MD, PhD Research Center for Vitamins and Vaccines, Bandim Health Project, Statens Serum Institut, Denmark and Bandim Health Project, Guinea-Bissau

2 Elimination targets

3 Strategies Routine vaccinations Birth 6w 10w 14w 9 months BCG+ 3*DTP+ 3* Measles vaccine Campaigns >1,000,000,000 doses of Measles Vaccine >10,000,000,000 doses of Oral Polio Vaccine

4 Purpose and Evaluation Campaigns conducted to Achieve high vaccination coverage To reach children not reached by the routine programme Monitored by Coverage: Doses given / estimated target population Specific disease protection / incidence

5 Targeted effects Reported measles cases by year WHO: Global measles and rubella strategic plan:

6 Estimated impact on mortality Small Measles mortality has been reduced by 75% since 2000 Polio infections have been reduced by 99% since 1988 Source: WHO But with non-specific /off-targeted effects -> campaigns could have much wider effects.

7 Bandim Health Project A platform for testing real-life effects of health interventions Guinea-Bissau Rural Guinea-Bissau Regular home visits Rural Guinea-Bissau Urban Guinea-Bissau Rural Guinea-Bissau > 100,000 individuals in 6 suburban districts > 100,000 individuals in 182 village clusters

8 Guinea-Bissau : 19 Campaigns with Oral Polio Vaccine 3 Campaigns with Measles Vaccine 10 Campaigns with Vitamin A 1 Campaign with H1N missing vaccine 2004 Dec 2005 May 2006 May 2007 June 2008 July 2009 Mar May H1N1 Mar July 2012 Dec 2012 Aug 2014 Dec Jan 2009 Jan April Dec April 2011 Mar 2012 May , no vaccines Other vaccines

9 Measles vaccination campaign May2006, no vaccines Other vaccines

10 Measles vaccination campaign Results removed

11 Boosting with measles vaccine in previous studies 4½-8 mo 9 mo Follow-up Observational study : MRR=0.41 ( ) Randomised trial : MRR=0.71 ( ) Aaby, BMJ, 1993 and Aaby, BMJ,

12 Conclusion Measles vaccination campaign Prevent measles and mortality from other causes than measles Especially among those previously vaccinated

13 Oral Polio Vaccine

14 Off-Target Effects of Oral Polio Vaccine First campaign in Bissau 1998: Mortality March-Dec 1998 campaign in 1998 age groups Mortality rate ratio vs. No 0-5 months 0.56 ( ) 0-4 years 0.67 ( ) Aaby, Vaccine, 2005

15 vaccination campaigns in Guinea-Bissau Urban Bissau Trials 2003 missing vaccine, no vaccines Other vaccines Dec 2005 May May 2007 Jan 2009 June 2008 Jan July 2009 Mar April May H1N1 Dec Mar 2011 April Mar 2012 July 2012 Dec May 2013 Aug Dec 2014

16 Urban Bissau Trials 2003 missing vaccine, no vaccines Other vaccines Dec 2005 May May 2007 Jan 2009 June 2008 Jan July 2009 Mar April May H1N1 Dec Mar 2011 April Mar 2012 July 2012 Dec May 2013 Aug Dec 2014 vaccination campaigns in Guinea-Bissau

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18 0 50 Urban Bissau: Under 5-years mortality Campaigns Year MDG4 reached: 68% reduction from /1000 to 68/1000

19 to be replaced by IPV

20 IPV Effects Birth IPV 4-6 mo IPV 9 mo Four trials in Guinea-Bissau IPV as a control vaccine Aaby, PIDJ, 2007

21 IPV Effects Female / Male Mortality Rate Ratio Birth 4-6 mo IPV 9 mo 1.52 ( ) 0.88 ( ) P=0.025 Aaby, PIDJ, 2007

22 Conclusion Purpose of campaigns Reach those not reached Eliminate measles and polio

23 0 50 Conclusion Purpose of campaigns Reach those not reached Eliminate measles and polio Little effect expected on mortality Real life observation Lower Mortality Especially among previously vaccinated children Year

24 Bandim Health Project and Research Center for Vitamins and Vaccines (CVIVA)